Paper machine headbox with adjustable partitions therein to regulate stock flow

ABSTRACT

A headbox with first and second partitions therein which are adjustable with respect to one another and the headbox to define a feed chamber, a holding chamber, and an outflow chamber, and which the function to regulate the rate at which stock flows from the slice. The partitions are moved by rack and pinions located externally of the headbox, the first partition pivoting around its upper end and the second partition pivoting at a point intermediate its ends. Perforated rolls are located in the feed chamber and outflow chamber to facilitate the entwining of stock fibers.

March 14, 1972 TADASH; KOBAYA5H| 3,649,448

HWI-R MACHINE HEADBOX WITH ADJUSTABLE IAV'TITIONS 'FHEHEN 'VO REGUT'ATV.STOCK FLOW Z Sheets-Sheet Filed Dec. 30, 1969 Inllmwmll.. 1 l l l||...1.---............-------- THD/91m ATTORNEY March 14, 1972 TADASHIKOBAYASHI 3,649,448

IHM( MACHLNL HUADBOX WITH ADJUSTABLE IARTITINS 'VHERETN TO REGULATESTOCK FLOW Film1 Dec. 160, ,1%0 3 Sheets-Sheet 2 FiQZ Fg ATTORNEY March14, 1972 TADAsl-u KOBAYASHI 3,649,448

APEJR MACHINE HEADBOX WITH ADJUSTABLE PARTITIONS THEREIN TO REGULATESTOCK FLOW Flled Deo. 30, v19659 5 Sheets-Sheet 5 Fig4 ENTOR ATTORNEY3,649,448 PAPER MACHINE HEADBOX WITH ADJUSTABLE gTITIONS THEREIN TOREGULATE STOCK W Tadashi Kobayashi, 227 Mitoshima, Fuji-shi,Shzuoka-ken, Tokyo, Japan Filed Dec. 30, 1969, Ser. No. 889,039 Int. Cl.D21f I/02 U.S. Cl. 162-343 5 Claims ABSTRACT OF THE DISCLOSURE A headboxwith rst and second partitions therein which are adjustable with respectto one another and the headbox to dene a feed chamber, a holdingchamber, and an outflow chamber, and which function to regulate the rateat which stock flows from the slice. The partitions are moved by rackand pinions located externally of the headbox, the first partitionpivoting around its upper end and the second partition pivoting at apoint intermediate its ends. Perforated rolls are located in the feedchamber and outtiow chamber to facilitate the entwining of stock fibers.

BACKGROUND OF THE 'INVENTION This invention relates to a headbox used tosupply paper stock onto a Wire or a screen in a papermaking machine.

Generally, paper of best texture can be obtained when stock fibers areallowed to settle by gravity naturally and uniformly in all horizontaldirections as it is dewatered on the wire. This happens only when therunning speed of the wire is in agreement with the speed of stockflowing out of the slice. Especially, when the stock flow speed ishigher than the Wire speed, stock fibers tend to stand up in relation tothe surface of the wire, thus unfavorably affecting the structure of thepaper layer.

Since the stock flow speed depends on the head of the stock in theheadbox, it is essential that the stock maintain the head correspondingto the wire speed so that there is a more nearly random orientation ofthe fibres of the paper.

The desired stock ow from the headbox depends on the consistency of thestock. If the heaviness of the paper is to be constant, the stock owfrom the slice must be greater when the stock consistency is lower, andvice versa. Consequently, the desired sectional area of the stock ow isdependent on the stock consistency. In other words, if the width of thewire in the transverse direction (or the direction of the paper width)is constant, the lvertical dimension of the slice should be larger whenthe stock consistency is low, and vice versa. Moreover, whether theslice is wide or narrow vertically, the stock must maintain the headcorresponding to the wire speed.

OBJECT OF THE INVENTION Thus, the present invention contemplatesarrangements to produce paper of particular weights and excellentquality by enabling one to vary the stock head in the head-box promptly,as desired, in accordance with wire speed changes so that the stock owspeed will agree with the wire speed; and also enabling one to vary thestock head in the headboX promptly, as desired, in accordance with sliceopening changes due to stock consistency changes, so that the stock flowspeed will agree with the wire speed, thus making it possible to producegood paper.

ted States Patent O 3,649,448 Patented Max'. 14, 1972 Fice SUMMARY OFTHE INVENTION .To achieve the foregoing object, generally speaking, thepresent invention contemplates a headbox which is divided into threechambers, namely, a stock outflow chamber having a slice through whichstock hows out, a holding chamber in which stock to be supplied to theoutow chamber is held temporarily, and a feed chamber which has a stockinlet and which supplies stock to the holding chamber. The outflowchamber and holding chamber are separated from each other by a rstpartition which enables one to adjust the stock flow from the holdingchamber to the outflow chamber. The holding chamber and the feed chamberare separated from each other by a second partition which enables one toadjust the stock llow from the feed chamber to the holding chamber. Byadjusting the openings of each of these partitions, it is possible tovary the stock head as desired in response to wire speed changes andstock consistency changes.

Other objects and advantages of the invention will be more readilyapparent from the following detailed description, when taken togetherwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a vertical section of aheadboX according to the invention;

FIG. 2 is a diagrammatic vertical section of the headbox with the stockhead adjusted to meet an increase in wire speed;

FIG. 3 is a diagrammatic vertical section of the headbox with the stockhead adjusted to meet a decrease in wire speed;

FIG. 4 is a diagrammatic vertical section of the head- Ibox with thestock head adjusted to meet an increase in stock consistency; and,

FIG. 5 is a diagrammatic vertical section of the headbox with the stockhead adjusted to meet a decrease in stock consistency.

DETAILED DESCRIPTION A box 1, constituting the main body of a headboxaccording to the present invention, is divided into three chambers;namely, a stock outflow chamber A, a stock holding chamber B adjacentthereto, and a stock feed chamber C located above these chambers. Theoutow chamber A has a slice 2 through which stock flow out. The holdingchamber B is adjacent to the outflow chamber A and separated therefromby a partition a which permits a controlled stock ow from the holdingchamber B to the outow chamber A. The feed chamber C, having a stockinlet 3 through which stock is introduced from an outside source, is solocated as to feed the holding chamber B chiefly by gravity andseparated therefrom by a partition b which permits of a controlled stockflow from the feed chamber C to the holding chamber B. The partition ahas a pivot 5 at the top and can be turned right and left so that itslower end 4. will control the stock ow from the holding chamber B to theoutflow chamber A. The partition b is held like a lever on a fulcrum 7and can be turned right and left so that its lower end 6 will controlthe stock ow from the feed chamber C to the holding chamber B. Stockintroduced through the stock inlet 3 enters the feed chamber C, passes aflow clearance T which can be adjusted by the partition b, flows intothe holding chamber B, then passes a flow clearance S which can beadjusted by the partition a, and enters the outow box A. By adjustingthe partitions a and b, therefore, it is possible to vary the stock headH as desired in accordance with the wire speed P, namely, so that thespeed 3 of stock flowing out of a slice 2 when its vertical dimension isW will agree with the wire speed P.

Thus, the partition b is equipped at the top with a rack 8 and a pinion9 by which the partition b can be controlled from outside the box 1. Asimilar means including rack S and pinion 9' and 5 enables one tocontrol the partition a from outside the box 1. The outfiow chamber Aand the holding chamber B have transparent graduated guage pipes 10 and11 shown on FIG. l only, so that the stock head in each chamber can beseen from the outside, and thus the heads may be adjusted eithermanually or automatically.

The partition a is arcuate at the lower end 4, and runs smoothly andstraightly therefrom to the pivot 5. A pin 4" and guide slot 4 may beprovided to insure straight movement as is conventional. The partition bis arcuate at the lower end 6, and runs smoothly and straightly upwardtherefrom including the part around the fulcrum 7. The box 1 alsocontains perforated rolls 12 and 13 installed behnd the slice 2 andabove the stock inlet 3, respectively, to facilitate the entwinin'g ofstock fibers, and an agitating roll 14 installed in an upper part of theoutow chamber to prevent stock masses from forming. These are meansfacilitating a random arrangement of :fibres in the suspension. Theslice 2 is nozzle-shaped, and its upper lip 2' is attached to the box 1'via a pivot 15 and can be controlled by a rod 16 to vary the opening ofthe slice 2. Rod 16 may be moved by any conventional means 21 such as apiston-cylinder, rack and pinion, or the like.

The means of adjustment according to the present invention, are moreparticularly described by the following examples.

Example l When the wire speed P has increased or is desired to beincreased While the stock consistency is to be kept constant, the stockhead H can be increased to H accordingly by the following procedure: Asshown in FIG. 2, widening the liow clearances S and T increases thestock flow into the holding chamber B and into the outiiow chamber A,respectively, resulting in an increase in stock head H. As soon as thehead reaches the level H required for the increased wire speed P', thetiow clearances S and T :are reduced so that the inflow through them,will again equal the outflow through the vertical dimension W of theslice 2. Thus, with the stock head maintained at a higher level H', thestock will flow out of the slice 2 at the sarne speed as the increasedlWire speed P'.

Example 2 When the vmre speed P has decreased or is desired to bedecreased while the stock consistency is to be kept constant, the 'stockhead I-I can be decreased accordingly by the following procedure: Asshown in FIG. 3, reduce the ow clearance T and make it narrower than theflow clearance S and the vertical dimension W of the slice 2. Thisdecreases the stock flow into the outflow chamber A and into the holdingchamber B, resulting in a decrease in stock head H. As soon as the headreaches the level H" corresponding to the decreased wire speed P", Widenthe flow clearance T so that the iiow through it will equal that throughthe flow clearance S and the vertical dimension W. Thus, with the stockhead maintained at H", the stock will flow out of the slice 2 at thesame speed as the decreased wire speed P".

Example 3 When the stock consistency has been reduced while the Wirespeed P and the stock head H are to be kept constant, that is, when thevertical dimension of the slice 2 has lbeen increased from W to W', as'shown in FIG. 4, Widen the flow clearance S to S', so that it willequal the increased vertical dimension W. This causes the stock head Hto go down temporarily. Then increase the tiow clearance T and make itwider than the iiow clearance S and the vertical dimension W. This makesthe stock low from the feed chamber `C to the vholding chamber B greaterthan the flow that goes out of the outflow chamber A, with the resultthat the stock head goes up again. As soon as the head reaches H, makethe flow clearances T and S equal to that of the vertical dimension W'.Thus, with the stock head maintained at H, the stock will flow out ofthe slice 2 with the increased vertical dimension W' at the same speedas the wire speed P.

Example 4 When the stock consistency has been increased while the wirespeed P and the stock head H are to be kept constant, that is, when thevertical dimension of the slice 2 has been reduced from W to W, as shownin FIG. 5, the stock head would go up if the headbox were kept in thiscondition. Therefore, reduce the flow clearance T and make it less thanthat of the vertical dimension W. This reduces the stock ow into theholding chamber B and into the outflow chamber A, resulting in adecrease in stock head. As soon as the stock head reaches H, bring theow clearance from T to T and make it equal that of the verticalclearance W. Thus, with the stock head maintained at H, the stock willflow out of the slice 2 with the reduced vertical dimension W" at thesame speed as the wire speed P.

In each of the above Examples l through 4, the flow of stock suppliedfrom the stock inlet 3 is constant at all times. This need not always bethe case, but is the usual case.

ln the present invention as described above, coordinated adjustment ofthe two partitions provided in the box makes it possible immediately tocause stock to ow out of the slice at the same speed as the Wire speedwhenever a change has occurred in wire speed or a new wire speed hasbeen used during a papermaking run; and when the opening of the stockfeeding slice has been varied in accordance with the stock consistency,it is possible to adjust the stock flow in accordance with the sliceopening so that the speed of stock from the slice will equal the wirespeed, thus ensuring the production of highquality paper. Moreover, wirespeed is simply related to the various spacings which are also simplyrelated to each other. This facilitates adjustments.

It is to be observed therefore that the present invention provides for aheadbox which comprises a vertical elongated box 1. There is a stockinlet 3 toward the upper portion of box 11 with a feed chamber (C) insaid box including a trough 19 disposed over the stock inlet, receivingstock from said stock inlet, and a curved wall 20 with a lower outerend, guiding stock flowing upwards through said trough over said curvedwall and into the lower portion of the feed chamber (A). There is adriven perforated roll 13 in the trough to entwine stock libres passingtherethrough. In the feed chamber is located a first partition b withupper and lower ends, and a fulcrum 7 intermediate said ends,substantially vertically disposed for movement about said fulcrum 7,including a rack and pinion l8, 9 exterior to said first partition upperend for moving said partition. Below the feed chamber is located aholding chamber (B) with a curved flow clearance at the lower endthereof. A second partition a defines on one portion the holdingchamber, and on the other portion the feed chamber, and a flow clearancebetween said iirst and second partitions, said second partition beingsubstantially vertically disposed, pivoted at its upper end to saidcurved wall outer end, said lower end extending into said flow clearanceand having an arcuate curvature matching that of said flow clearance,the pivoting of said first and second partitions regulating the passageof stock. Adjacent said holding chamber (B) is an exit chamber in saidbox lower section, including a slice 2 at the lower end thereof fordisgorging stock onto paper forming means. A third partition 17, definesthe outer wall of the holding chamber from the inner wall of the exitchamber, said third partition 17 being substantially verticallydisposed. A slice upper lip 2 connected at its inner end to said thirdpartition, e.g., by means of a pivot including a rod 16 extendingoutwards of said box, said rod serving to adjust the position of saidslice upper lip 2 to vary the size of said slice opening. There is adriven lower perforated roll 12, in said exit chamber lower end, forentwining stock ibers; and, an upper driven agitator 14, in the upperpart of said exit chamber, for breaking up aggregations of bers.

Although the present invention has been described in conjunction with anembodiment suggesting manual adjustment, the various adjustmentsnecessary because of the liquid levels, Wire speed, etc. may be measuredautomatically, eg., by a light beam and photocell. These components canin turn adjust a cam which can act on the other components hereindescribed.

What is claimed is:

1. In a paperrnaking machine, a headbox, said headbox having walls and'being divided into a stock outilow chamber having a slice 'for feedingstock, a holding chamber communicating with said outflow chamber inwhich stock to be supplied to said outflow chamber is temporarily held,and a feed chamber communicating with said holding chamber equipped witha stock inlet for introducing stock from an outside source to the topportion of said headbox, said outiow chamber and holding chamber beingseparated from each other -by first rigid partition means capable ofcontrolling the stock flow from the holding chamber to the outflowchamber, means for moving said rst partition means with respect to oneof said headbox walls to adjust the space between the same to controlstock flow therebetween, said rst partition means being pivoted at itsupper end to said headbox, and the said holding chamber and feed chamberbeing separated from each other by second rigid partition means capableof controlling the stock flow from the feed chamber to the holdingchamber, means for moving said second partition means -with respect tosaid iirst partition means to adjust the space between the same tocontrol stock flow therebetween, said second partition means beingpivoted intermediate its ends to said headbox, and the means for movingsaid second partition means causing the same to rotate about its pivot,the stock flow being adjusted so that the stock head will be set inaccordance with changes in wire speed and in stock consistency.

2. In a paper making machine according to claim 1, wherein said meansifor moving said iirst and second partitions includes rack and pinionmeans external to said headbox mechanically connected to said first andsecond partitions.

3. A headbox, comprising in combination:

(a) a vertically elongated box (1);

(b) a stock inlet (3) opening into the upper portion of the box;

(c) a feed chamber (C) in said box including a trough connected to saidstock inlet, receiving stock from said stock inlet, and a wall guidingstock flowing upwards through said trough into a lower section of saidfeed chamber (C);

(d) a rst partition (b) in said feed chamber, substantially verticallydisposed for movement therein, including a rack and pinion (8, 9)exterior t0 said first partition connected to the upper end of saidpartition for moving said partition;

(e) a holding chamber (B) adjacent and below said feed chamber (C) witha lower flow clearance at the lower end thereof;

(f) a second partition (a) defining on its lower portion said holdingchamber, and on the upper portion said feed chamber, and an upper flowclearance between said lirst and second partitions, said secondpartition being substantially vertically disposed, pivoted at its upperend to said box, said lower end extending into said lower flow clearanceand being shaped to match said lower low clearance, the pivoting of saidtirst and second partitions regulating the passage of stock;

(g) an outllow chamber (A), adjacent said holding chamber (B) in thelower portion of the box, including a slice (2) at the lower end thereoffor disgorging stock onto paper forming means;

(h) a third partition (17), defining the outer wall of said holdingchamber, said third partition (17) being substantially verticallydisposed; and

(i) a slice upper lip (2) connected at its inner end to said thirdpartition including adjusting means (16) extending out-wards of saidbox, actuating means for moving said adjusting means serving to adjustthe position of said slice upper lip (2) to vary the size of said sliceopening.

4. A headbox as claimed in claim 3, said third partition 17 having apivot (15) at its lower end, said slice upper lip (2') being pivotedthereto, said adjusting means being a rod (16).

5. A headbox as claimed in claim 3, said trough being disposed over saidstock inlet.

References Cited UNITED STATES PATENTS 3,236,725 2/1966 Goldsmith i162--336 3,135,654 6/1964 Fair 162-336 3,164,513 l/1965 Calehuf 162-336X FRANK W. MIGA, Primary Examiner R. H. TUSHIN, Assistant Examiner U.S.Cl. X.R. 162-336

